Molecular Biology Practice Test 7

1. Tryptophan operon in E. coli is a repressible operon.

False

True

2. Which of the following is false about bacterial tryptophan operon?

When tryptophan supply is insufficient the tryptophan operon activates

It has two kinds of regulation system

The complex of repressor with co-repressor on binding to the operator blocks transcription

The co-repressor is the catabolite activator protein

3. Glucose, as the carbon source, is the first choice by bacteria even if other sugars are available. The mechanism behind this selectivity is ___________

Catabolite repression

Enzyme repression

Operon repression

Glucose utilization

4. Immunoglobulin enhancers are active in which of the following cell types?

Macrophages

B lymphocytes

Megakaryocytes

T lymphocytes

5. Which of the following disease is caused by missense mutation?

Hemophilia

Sickle cell anemia

Cystic fibriosis

Thalassemia

6. Initiation of glycosylation occurs in the Golgi body.

True

False

7. Which of the following about the enhancers is false?

They are tissue specific

They function as promoter sequences

They work as both cis and trans-acting sequences

They function in orientation

8. For the process of autophagy the formation of vesicles occurs. The membrane of these vesicles are derived from ___________

Mitochondria

Nuclear membrane

Cell membrane

Golgi membrane

9. Operons are ___________

not able to bind to proteins

smaller in lower eukaryotes and longer in higher eukaryotes

found in some eukaryotes

of approximately uniform size

10. How many types of modification are possible in eukaryotes by addition of lipids?